Initially, asteroid-watchers said the 71-foot-wide (22-meter-wide) space rock would come within 223,000 miles (359,000 kilometers), or slightly within the moon's orbit. The refined trajectory, however, showed 2010 GA6 coming no closer than 270,000 miles (434,000 kilometers), or slightly beyond the moon's orbit.

The asteroid was discovered only recently by the Catalina Sky Survey in Tucson, Ariz.

NASA routinely tracks asteroids and comets that make close approaches to Earth. In January, another small asteroid made an even closer approach to Earth, passing within 76,000 miles.

"Flybys of near-Earth objects within the moon's orbit occur every few weeks," Don Yeomans of the Near Earth Object Office said in a statement.

This report includes information from msnbc.com and The Associated Press.